Hyundai i20 Alternator: Specs, Fitment & Common Faults

On the i20, resting and running voltage figures genuinely reveal whether the alternator is charging correctly.

Illustration for editorial purposes

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OEM Part Number: 37300-03300

Accuracy note: confirmed shared reference across 1.2 petrol i10, i20, and Kia Picanto, since Hyundai and Kia use common engine and electrical components.

1.2 petrol, 70 Amp	Hyundai/Kia OEM: 37300-03300
Higher trims/automatic variants	A genuinely different, typically higher-amperage alternator applies to versions with more standard electrical equipment — confirm the amp rating on your existing unit before ordering

A Genuinely Useful Diagnostic Benchmark Worth Knowing — Hyundai i20 Alternator

If you're trying to determine whether the alternator is genuinely at fault, this is worth knowing: with the engine off, battery voltage should read between roughly 12.4 and 12.7 volts. Once started, this should rise to between roughly 13.7 and 14.7 volts if charging correctly. If a warning light appears while driving, turning off every accessory you safely can and seeing if the warning clears tells you whether there's still enough charging capacity to get you somewhere safely.

A genuinely important safety warning worth knowing before attempting a DIY alternator swap: one documented case saw the positive battery cable briefly make contact with the exhaust manifold shield during removal, causing a spark. It's worth fully disconnecting the battery's negative terminal first and routing cables carefully away from hot exhaust components.

It's also worth knowing that on some models, the fuse protecting the alternator circuit isn't a conventional, easily replaceable fuse at all, but a shunt in a different physical location.

Hyundai i20 Alternator: Often Blamed on the Battery Instead

Early on, a weak Hyundai i20 battery and a dying alternator look almost identical — dim lights, sluggish starts, a car that won't hold its charge — which is exactly why so many people fit a new battery and end up back at the garage weeks later, the actual fault still unaddressed.

Before you buy: alternator output rating varies by engine size and trim, particularly on cars with more onboard electronics. Always confirm against your VIN before ordering.

Hyundai i20 Alternator: What It Does

On the Hyundai i20, while the engine runs, the alternator generates the electricity that charges the battery and powers the car's electrical systems directly. With a healthy alternator, the battery's real job becomes starting the engine and covering brief demand spikes, rather than running the electronics on its own.

Find Hyundai i20 Alternator Here!

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Hyundai i20 Alternator: Warning Signs, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Alternator Guide for symptoms to watch for (plus a genuinely useful two-minute test to confirm it's not the battery instead), confirming the right amperage and fitment against your VIN, and which brands are worth trusting.

More Hyundai Alternator

The same part, covered across other Hyundai models.